Blood Pressure PDF

Blood pressure Dr. Sethu Ngubane  Blood Pressure (BP)  Force exerted by circulating blood on the walls of blood vessels  Highest in the aorta and reduced as blood flows through other blood vessels  Often referred to as arterial blood pressure  Measured using invasive and non-invas...

Blood pressure Dr. Sethu Ngubane  Blood Pressure (BP)  Force exerted by circulating blood on the walls of blood vessels  Highest in the aorta and reduced as blood flows through other blood vessels  Often referred to as arterial blood pressure  Measured using invasive and non-invasive methods  Blood Pressure Values Systolic Diastolic (mmHg) (mmHg) Normal 100-119 60-79 Hypotension < 100 < 60 Prehypertension 120-139 80-89 Hypertension ≥140 ≥90 1. Stage 1 140-159 90-99 2. Stage 2 ≥ 160 ≥ 100 (Adapted from Starr and McMillan: Circulation-The Heart and Blood Vessels)  Pulse Pressure  Pulse pressure= systolic pressure minus diastolic pressure  It represents the force that the heart generates each time it contracts.  Mean arterial pressure (MAP) represents average arterial pressure during cardiac cycle  MAP=diastolic + 1/3 pulse pressure  Blood Pressure (BP)  Controlled mainly by heart rate, stroke volume and peripheral resistance  An increase in any of these can result in increased BP  Peripheral Resistance Resistance of the arteries to blood flow As the arteries constrict, the resistance increases, as they dilate, resistance decreases Autonomic activity: The sympathetic and parasympathetic nervous systems. The sympathetic nervous system prepares your body for physical and mental activity. heart beats faster and stronger, Respiration is increased, and inhibits digestion. The parasympathetic nervous system is responsible for bodily functions when we are at rest: it stimulates digestion, helps with relaxation. But the sympathetic and parasympathetic nervous systems do not always work in opposite directions; they sometimes complement each other too.  Blood pressure measurements  Measured in mmHg  Values in healthy adult